mirror_zfs/include/sys/vmsystm.h
Brian Behlendorf ea3e6ca9e5 kmem_cache hardening and performance improvements
- Added slab work queue task which gradually ages and free's slabs
  from the cache which have not been used recently.
- Optimized slab packing algorithm to ensure each slab contains the
  maximum number of objects without create to large a slab.
- Fix deadlock, we can never call kv_free() under the skc_lock.  We
  now unlink the objects and slabs from the cache itself and attach
  them to a private work list.  The contents of the list are then
  subsequently freed outside the spin lock.
- Move magazine create/destroy operation on to local cpu.
- Further performace optimizations by minimize the usage of the large
  per-cache skc_lock.  This includes the addition of KMC_BIT_REAPING
  bit mask which is used to prevent concurrent reaping, and to defer
  new slab creation when reaping is occuring.
- Add KMC_BIT_DESTROYING bit mask which is set when the cache is being
  destroyed, this is used to catch any task accessing the cache while
  it is being destroyed.
- Add comments to all the functions and additional comments to try
  and make everything as clear as possible.
- Major cleanup and additions to the SPLAT kmem tests to more
  rigerously stress the cache implementation and look for any problems.
  This includes correctness and performance tests.
- Updated portable work queue interfaces
2009-01-30 20:54:49 -08:00

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C

/*
* This file is part of the SPL: Solaris Porting Layer.
*
* Copyright (c) 2008 Lawrence Livermore National Security, LLC.
* Produced at Lawrence Livermore National Laboratory
* Written by:
* Brian Behlendorf <behlendorf1@llnl.gov>,
* Herb Wartens <wartens2@llnl.gov>,
* Jim Garlick <garlick@llnl.gov>
* UCRL-CODE-235197
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef _SPL_VMSYSTM_H
#define _SPL_VMSYSTM_H
#include <linux/mm.h>
#include <linux/swap.h>
#include <sys/types.h>
#include <asm/uaccess.h>
extern vmem_t *zio_alloc_arena; /* arena for zio caches */
#define physmem num_physpages
#define freemem nr_free_pages()
#define minfree 0
#define needfree 0 /* # of needed pages */
#define ptob(pages) (pages * PAGE_SIZE)
#define membar_producer() smp_wmb()
#define xcopyin(from, to, size) copy_from_user(to, from, size)
#define xcopyout(from, to, size) copy_to_user(to, from, size)
static __inline__ int
copyin(const void *from, void *to, size_t len)
{
/* On error copyin routine returns -1 */
if (xcopyin(from, to, len))
return -1;
return 0;
}
static __inline__ int
copyout(const void *from, void *to, size_t len)
{
/* On error copyout routine returns -1 */
if (xcopyout(from, to, len))
return -1;
return 0;
}
static __inline__ int
copyinstr(const void *from, void *to, size_t len, size_t *done)
{
size_t rc;
if (len == 0)
return -ENAMETOOLONG;
/* XXX: Should return ENAMETOOLONG if 'strlen(from) > len' */
memset(to, 0, len);
rc = copyin(from, to, len - 1);
if (done != NULL)
*done = rc;
return 0;
}
#if 0
/* The average number of free pages over the last 5 seconds */
#define avefree 0
/* The average number of free pages over the last 30 seconds */
#define avefree30 0
/* A guess as to how much memory has been promised to
* processes but not yet allocated */
#define deficit 0
/* A bootlean the controls the setting of deficit */
#define desperate
/* When free memory is above this limit, no paging or swapping is done */
#define lotsfree 0
/* When free memory is above this limit, swapping is not performed */
#define desfree 0
#endif
#endif /* SPL_VMSYSTM_H */